Method of destroying insects.



P. S. SMITH.

METHOD OF DESTROYING INSECTS. APPLIOATION FILED 11111.7,1911.

1,016,790. Patented Feb. 6, 1912.

2 SHEETS-SHEET 1.

WM/"mo l Sme/wz 3% I Z i 41 F.. S. SMITH.

METHODOP DESTROYING INSECTS. 1

APPLICATION FILED 11111.1, 1911.

Patented Feb. 6, 1912.

2 SHEETS-SHBET 2.

UNITED STATES PATENT onnion,

FRANKLIN s. SMITH, or PHILADELPHIA, PENNSYLVANIA.

METHOD DESTROYING INSECTS. I

To all whom. it may concern: i

Be it known that I, FRANKLIN S. SMITH, a citizen of the United States,residing in the city and county of Philadelphia, State of Pennsylvania,have invented a' certain new; and useful Method of Destroying Insects,of which the following is a specification.

My invention relates to a method of destroying insects and their eggs,larvae or pupae, particularly those which infe st and which aredestructive of various articles of merchandise found in the industrialarts.

Without attempting to enumerate all of the various articles and objectswhich may be treated according to my invention for the purpose ofdestroying the; destructive insects which may infest and may destroythem, I may mention food products, such as cereals, prepared breakfastfoods of the va= rious kinds, dried fruits, flour, figs, etc.;

tobacco, either in the leaf state or after it,

has been converted into some form of manu factured product, such ascigars or cigarettes; wearing apparel, such as fiurs, woolens, etc;; andbooks, papers, etc.

It is known to almost every one that all of the various articles namedare liable to be and frequently are injured by. various insects, worms,etc. which may attack them. Great quantities of clothing,' food stuffs,such as cereals; tobacco; etc. are destroyed during the course of everyyear by the various insects etc. which are peculiar thereto.

It is known that insects; which may attack and injure certain articlesdo not atiack t is also known that there is a species ofworm, more aptto befoun in warmer countries, commonly called the book worm, whichattacks books, papers, etc. and causes great injury and damage thereto.It may be stated that many species of the book Wormare known.

The principle involved my invention 1 may be employed also for thepurpose of destroying the various insects, their eggs, larvae or pupaewhich attack fruitand other trees and cause their blight and frequentlytheir death.

Specification of Letters Patent.

'7 Application filed January 7, 1911. Serial No. 601,282.

' rule.

,Patented Feb. 6, 1912.

ment of my new method is not limited to the articles and objectsdesignated above but may be employed for the treatment of many otherobjects for the destruction of such insects, 'etc., as may infest'themand cause 4 It is to be understood that the employ- K injury,deterioration and frequently the destruction thereof.

My invention consists in the subjectionof insects, their eggs, larvae orpupae, to the actlon of electrical discharges by which they aredestroyed. ,In the actual; practice "and use of my method the article orarticles infested with the insects, their eggs, larvae or pupae, wouldbe subjected to the action nor as tocause the elimination anddestruction of the said insects, etc., without injury to or in any waycausing the deterioration of the quality or character of thesaid article01' articles Care must be exercised in the practicing I of my inventionto prevent the formation of sparks in the .electrical discharge of toogreat capacity. This is particularly true in cases where-the articlewhich is subjected to w the action of the electrical discharge isreadilyoxidized and carbonized.

I may employ in my new method-discharges caused eitherbv oscillation orunidirectional currents. In the drawings I have illustrated means forproducing oscillating currents but the mannertinwhich the current in amachine, such as is shown, for

instance, in Figures 4 and 5 of the drawings, may be converted "from anoscillating into a uni-directional current is well known to those havingknowledge of the electrical art.

In the carrying out and practicing of my" invention, it is necessarygenerally that the objects and articles treated shall" be free frommetallic. substances though there are some cases which form an exceptionto this should be present any metallic substance or substances they.would act as isolated capacitles and would cause a,v condensation 65 ofthe electrical discharges in such manof the electrical discharges whichpass through the objects or articles and thus prevent contact' of thecurrent with certain portions of the object or article being treatedadjacent to such metallic substances, wlth the result that .suchportions would be unaffected and unacted upon by the discharge throughthe article or object being treated and the insects, etc., present insuch portlons,

would be left unharmed.

Cereals and breakfast foods generally may be treated in bulk or in theusual card I board boxes in which they are sold but when treated in suchboxes care should be taken 'to prevent the presence of metal upon saidboxes. Also cigars and cigarettes may be treated in bulk or in the boxesin which they are soldor marketed. The difficulty,

1 however, in treating cigars and cigarettes in boxes as suggested isthat such boxes are usuallyprovided with decoration which includes agreater. or less amount of metallic substances which would interferewith the successful operation of my invention and 25,

discovery in the treatment thereofin boxes; hence, cigars and cigarettespreferably should be treated inbulk and before being Q placed in theboxes in which they are marketed. m a 1 In the treatment of clothingcare must be exercised to prevent the presence of metalllc buttonsbecause if such buttons were presentthey would .act as isolatedcapacities as already indicated and cause a condensatlon of thedischarge at the points at which they are located so as to prevent theaction of the discharge upon the portions of the material of the garmentwhich are in proximity to and surround the said buttons, leaving theinsects, etc. on such portion unharmed.

In the use of my invention in the treatmentof articles such as are abovesuggested,

[care must be exercised to prevent their oxi-- dat'ion and carbonizationby the discharge sparks which are. of too great a capacity.

-.c ause injury to the articles themselves.

In the large number 0f experiments which I have heretofore carried outin 'the iii development of my. invention, I have discoveredtlfatwhen it,is ca'refull and intelligently practiced andused allo the insects,

in whatever stage, of their development whet eras eggs,- larvae,ipupae,or adults, whic may infest on-be'present in or upon an article whichfistreated, will be destroyed;

Asapparatus is necessary to the-practic I ing and carrying out of myinvention, I have illustrated diagrammatlcally a couple of formsofconstruction which may be employed but it will be understood that otherforms of apparatus than those illustrated may be employed or used topractice the same. a

In the drawings :-Fig. 1 is a top plan view of an apparatus embodying myinvention; Fig. 2 is a sectional side eleva tion of the same; Fig. 3 isan enlarged view on the line 33 of Fig. 1, showing more clearly a detailof.construction; Fig. 4 is a top plan view of a modified construction ofapparatus embodying my invention; and Fig. 5 is a sectional sideelevation of the construction shown in 'Fig. 4. 1

I Referring to the drawings :The numeral 1 designates a source ofalternating electric current; 2 a switch; and 3 a variable or adjustableresistance.

In Figs. 1 to 3 inclusive the resistance 3 is connected in. series withthe primary of a step-up'transformerA. .The condenser 5 is connected inparallel with the secondary coil .of the transformer 4. The primarycoils 6 of the Tesla coils 7 are connected-in multiple with thecondenser 5, and the spark gap, of known construction, and designated asa whole by the reference numeral 8, is connected in series with thecondenser 5 and the Tesla coils 7.. The revoluble member. 9 of the sparkgap is rotated by means of a motor 10. The opposite ends of thesecondary coils 12 of the Tesla coils are connected to oppositelydisposed electrodes 15 and 16. These electrodes are arranged 'in tworowsilas is indicated in Fig. 1 of the drawmgs, t e electrodes .in thetwo upper rows being arranged in staggered relation with respect to eachother, as is clearly shown in Fig. 1 of the drawings, while those in thetwo lower rows are arranged in staggered relation with respect to eachother in the same manner. v

- L The number of Tesla coils and the number of electrodes andarrangement of the latter may be varied as desired.

Preferably, though in some cases it may be found to be unnecessary, theelectrodes should respectively terminate in a single point in order thatall portions of the ob- .ject' or article being treated, whether inboxes or otherwise, may be subjected to the 120 action of the discharge.It has been found that ifelectrodes of considerable length andrespectively provided with a plurality of points are employed andarticles are treated in boxes, it happens that the discharge takes placebetween points of opposing electrodes which are nearest toalinement witha side of the said boxes along the said side so that the material in theboxes may not be acted upon. In such cases the-insects'or their eggs,.1arvae;or pupae which may be present in the articles and which it isdesired to destroy remain unaffected. The electrodes are supported indepressions or seats 18 and 19 formed in the plates 2Q and 21 of insu;lating material, such as glass or porcelain.

It will be understood that when the switch 2 is closed an electricdischarge takes place between the electrodes 15 and 16 suchdischargeconsisting of well defined sparks and also of what is known aseflluve, both of which are visibly apparent. Theplates 20 and 21 ofinsulating material are supported in any suitable manner, as for instance, upon posts or standards 25 and 26.

It will be observed that the electrodes 15 project a. short distancebelow the lower side or surface of the plate 20 while the ends of theelectrodes 16 are located a short distance below the upper side of theplate 21.

30 designates a conveyer of suitable nonconducting material supportedupon revoluble wheels 31 driven from any suitable source of power, bymeans of which articles to be treated are conveyed into and across thespace between the electrodes 15 and 16. The electrodes in therespectiverows should be arranged close together and those in therespective plates upon which they are sup ported should be in staggeredrelation with respect to each other, as indicated in Fig. 1.

It is desirable that the electrodes should be arranged closely togetherand in staggered relation, as illustrated, in order that as an articleis passed between the electrodes upon the conveyer 30 or by any othermeans supported intermediate the electrodes, all parts thereof should besubjected to the action of the discharge. In other words, there shouldbe no wide gaps in the line or curtain of discharge through which anarticle or portions of an article might be passed without being actedupon thereby.

In Figs. 4 and 5 the variable or adjustable resistance 3 is connected inseries with the primary coils of a number of step-up transformers 40which are connected in multiple with the source,1 of current. Theopposite ends of the secondary coils of the said transformers 40 areconnected with the electrodes 15 and 16 supported and arranged in seats18 and 19 formed in the insulating plates 20 and 21 in the same manneras is indicated in Figs. 1 to 3. The said insulating plates aresupported upon postsor standards 25 and 26 in the same manner asthecorresponding plates in Figs. 1 to 3 and the articles and objects areconveyed into and supported in position to be treated by means of aconveyer of insulating material 30 supported on revoluble wheels 31driven from any suitable source of power (not shown).

It may be noted that the construction illustrated in Figs. 1 to 3produces high frequency electrical oscillations mounting intothethousands per second, while that shown in Figs. 4 and 5 produces lowfrequency electrical oscillations of commercial or slightly higherfrequency.

In both forms of construct-ion as illustrated, the discharges areproduced by means of electrical oscillations but it will be understoodthat the same result may be etfected by the employment of dischargesproduced by a uni-directional current.

The manner of rectifying the current produced by an apparatus such as isshown in Figs. 4 and 5 so as to produce a unidirectional current is wellknown and need not be described herein.

In orderto operate the apparatus illustrated in Figs. 1 to 3 of thedrawings, the switch 2 should be closed and the motor 9 started. Thevariable or adjustable resisttrated in Figs. 4 and 5 the switch 2 shouldbe closed and thev variable or adjustable resistance 3 adjusted asdesired. In this form of construction the capacity of the dischargespark may be controlled tosome extent by adjusting the resistance 3 butit is principally dependent upon the transformers 40.

It may be noted here that to secure. the best results the distancebetween the electrodes 15 and the surface of the top portion of theconveyer or'other supporting means should be only slightly greater thanthe height or thickness of the objects or articles which are beingtreated in' the apparatus. I

As the articles being treated are placed, in position in the spacevbetween the electrodes they are acted upon by the electrical dischargewhich tak place between the said electrodes, the passage -of whichthrough the objects effects or causes the de struction and killing ofthe insects, their eggs, larva or pupae which may be present.

Inthe treatment of tobacco, whether it be in the form of cigars or inbundles or bales prior to being converted into a manufactured product orin any other form, the leaves thereof should be placed in the machine orapparatus sothat they extend substantially in parallel relation with thedirection of the lines of discharge of the electric sparks between theopposing electrodes. If cigars, for instance, are being treated, theyshould be supported with their ends upon the conveying beltor othermeans by which they are sustained in position between the electrodes fortreatment. By so arranging the tobacco the current acts upon all partsof the leaves'whioh may be included within apackage and within eachcigartif the towhereas, if th bacco isin the form of cigars) and thuseffectively destroys all of the insects, their eggs, larvae oz pupae, asthe case may be;

sparks extendvtransversely of the leaves they are apt to pass directlytherethrough without spreading over their surfaces and consequently arenot likely to destroy all of the insects, etc. It is also the case thatif the discharge sparks take place transversely of the leaves of thetobacco, it is likely that the easily carbonized, such as cereals, thecapacity of the discharges employed or used may be increased withoutdanger of causing oxidation and carbonization.

It is also necessary that the voltage of the apparatus employed shouldbe adjusted or varied to correspond with the capacity or conductivity ofthe article being treated. For instance,'the voltage used in treating acolumn of tobacco of a certain definite height should be less than thatemployed in the treatment of a column of the same height of some othersubstance, for instance, a cereal, of less conductivity.

In the employment of my invention in the treatment of tobacco, I havediscovered that the combined length of the sparks between the opposingelectrodes should be equal to one-third of the distance across thespace'between the same, because when the tobacco is placed in positionfor treatment it acts as a conductor so that thesparks will then extendalong the tobacco clear across the space. But in the treatment of othersubstances of less conductivity and less capacity than tobacco, it isnecessary that a voltage be employed which will occasion the productionof sparks of greater length than 1s necessary when tobacco is beingtreated in order that when such substances are placed in position to betreated the sparks will extend entirely across the space occupiedthereby. When treating cereals, for instance, the sparks should extendsubstantially entirely across the space between the electrodes before-the cereals are placed in position to be treated; It must beunderstood, however, that my invention is not limited to the exactlength of sparks above indicated but that their lengths may beconsiderably varied without departing from my invention.

The practicing of my invention is more satisfactorily and successfullycarried out when the insects, their eggs, larvae or pupae or articles onor in which they are located tobacco'is so placed that the are subjectedto the action of electrical discharges which cover or extend across aconsiderable area so that every part of the article and every insect,etc. wh1ch is passed through the field of the'discharge is acteduponthereby. I have discovered that the said insects, their eggs, larvae orpupae, are killed'or destroyed immediately by the'discharge sparks and Ihave discovered also that the said sparks seek out the said insects,eggs, larvae or pupae, wherever they may be in or upon the article anddestroy them.

In its broadest aspect my invention may be regardedas comprehending themethod of destroying insects, their eggs, larvae or pupae, by the actionof electrical discharges thereon; and in its practical operation it isemployed for the purpose of destroying such insects, their eggs, larvaeor pupae, as may infest and cause injury to and deterioration of thevarious articles of commerce and other objects hereinbefore suggestedand indicated.

Having thus described my invention, I claim 1. The method of treatingarticles and objects for the purpose of destroying the insects, theireggs, larvae or pupae which may infestthe same, which consists in theproduction of a plurality of independent electric discharges betweendifferent points and thereby forming a field of electric discharges andin subjecting the articles or objects to the said discharges, wherebythe insects, their eggs, larvae or pupae are subjected to the actionthereof and thereby destroyed.

2. The method of treating tobacco for the purpose of destroying theinsects, their eggs, larvae or pupae, which may infest the same, whichconsists in the production of an electrical discharge and subjecting thetobacco to the action of'said discharge with the planes of its leaves orportions of leaves in the same general direction as that in which thedischarge takes place to destroy such insects, their eggs, larvae orpupae.

3. The method of treating tobacco for the purpose'of destroying theinsects, their eggs, larvae or pupae, wh1ch may infest the same,

which consists in the arrangement of the tobacco with the planes of itsleaves or portions of leaves in substantially parallel relativity of thetobacco and subjecting the tobacco to the action of the said dischargewith the planes of its leaves or portions of its leaves extending in thesame general FRANKLIN S. SMITH; 5 direction as that of the sparks of thedis- In the presence of- 1 charge, whereby such insects, their eggs,GEO. H. WEmNER,

larvae or pupae are destroyed. CARRIE E. KLEIN-FEIDER;

In testimony thatI claim the foregoing as my invention, 1 have hereuntosigned my name this 4th day of January, A. D. 1911.

